package pers.zhang.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * @Classname CheckUtil
 * @Description TODO
 * @Date 2019/1/18 14:33
 * @Created by zhangkai
 */
public class CheckUtil {
    private static final  String token="cnkingz";
public static boolean checkSignature(String signature,String timeStamp,String nonce){
    String[] arr=new String[]{token,timeStamp,nonce};
    //排序
    Arrays.sort(arr);
    //生成字符串
    StringBuffer content =new StringBuffer();
    for(int i=0;i<arr.length;i++){
        content.append(arr[i]);
    }
    //sha1加密
    String temp=null;
    try {
        temp= getSha1(content.toString());
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
        System.out.println("加密失败");
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
        System.out.println("加密失败");
    }
    return temp.equals(signature);
}

    public static String getSha1(String str) throws NoSuchAlgorithmException, UnsupportedEncodingException {
        if (null == str || str.length() == 0){
            return null;
        }
        char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f'};
        try {
            MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
            mdTemp.update(str.getBytes("UTF-8"));

            byte[] md = mdTemp.digest();
            int j = md.length;
            char[] buf = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
                buf[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(buf);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

}
